A planer, planer-matcher, or moulder are similar machines widely used throughout the wood processing industry to turn rough workpieces into finished workpieces such as surfaced lumber and contoured shapes like molding, flooring and siding. The planer's primary function is to produce a desired cross-sectional profile with an adequate surface finish out of the rough workpiece being processed. The planer is one part of a group of equipment known as the planer mill.
Typically the planer processes material at speeds from 100 to 2000 feet per minute. The planer will typically remove between 0.050″ to 0.150″ from the overall height and width of most workpieces but more or less may be required depending on the application. Typical planers are used to process workpieces with cross-sectional dimensions from under 1″×1″ to 8″×25″.
FIG. 1 shows a diagram of the typical flow of material through a conventional prior art planer. The rough workpiece is typically fed on a table conveyor through a 90 degree transfer onto the planer infeed conveyor. The workpieces then typically feed single-file end-to-end through the planer. After the finished workpiece leaves the planer it typically turns 90 degrees onto an outfeed table conveyor where it continues on for further sorting and processing.
In modern planner mill installations a grading scanner is sometimes used after the planer to create a three-dimensional profile of each finished workpiece. This profile data contains cross-sectional information measured periodically along the length of each workpiece. The profile data of each workpiece is then used by the Graderman to determine the proper grade and optimal length of each workpiece.
FIGS. 2a and 2b show simplified side and top views of a typical prior art planer. The key elements of the planer as shown, are as follows:                a) Top and bottom feed rolls        b) Inside guide        c) Top and bottom planer heads        d) Top chip breaker        e) Pressure bar        f) Bed plate        g) Tail plate        h) Inside and outside planer heads        i) Side chip breaker        j) Top and bottom outfeed rolls        
The exact configuration and name given to each machine component may change based on manufacturer, model, and the material being processed.
When a typically configured planer is setup for a given production run the operator aligns the bed plate and the inside guide relative to the cutter heads to remove a fixed amount from the bottom and one side of each workpiece. The top cut and the remaining side cut are then made removing the balance of wood required to obtain the desired shape.
Applicant is aware of the following U.S. Pat. Nos. 5,761,979; 4,239,072; 4,449,557, 5,816,302; 5,853,038; 5,946,995; and 5,884,682.